Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M
CVE-2026-83813Twisted: DNS Response Spoofing in twisted.names Due to Missing Source Address Validation
Low 3.1
In plain English
A low-severity security flaw in twisted from twisted. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.names.dns.DNSDatagramProtocol accepts a UDP DNS response for a pending query when its 16-bit transaction ID matches but does not verify that the response came from the queried host and port. An attacker able to deliver a packet to the resolver's listening port with the correct transaction ID can inject a forged answer. The standard twisted.names.client.Resolver uses a new random source port for each query, increasing off-path attack complexity, while applications that reuse a DNSDatagramProtocol instance expose only the transaction-ID search space after the first query. A successful forgery can redirect hostname resolution and enable mail interception, server-side request forgery, or man-in-the-middle positioning. This issue is fixed in version 26.10.0rc1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | twisted | no fix listed | DEBIAN-CVE-2026-83813 |
| Debian:13 | twisted | no fix listed | DEBIAN-CVE-2026-83813 |
| Debian:14 | twisted | 26.10.0-1 | DEBIAN-CVE-2026-83813 |
| PyPI | twisted | 26.10.0rc1 | GHSA-jj36-9pvh-vj5r |
| Ubuntu:22.04:LTS | twisted | no fix listed | UBUNTU-CVE-2026-83813 |
| Ubuntu:24.04:LTS | twisted | no fix listed | UBUNTU-CVE-2026-83813 |
| Ubuntu:26.04:LTS | twisted | no fix listed | UBUNTU-CVE-2026-83813 |
| Ubuntu:26.10 | twisted | no fix listed | UBUNTU-CVE-2026-83813 |
Affected products (as reported)
Weakness: CWE-346 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://github.com/twisted/twisted/security/advisories/GHSA-jj36-9pvh-vj5r x_refsource_CONFIRM
- https://github.com/twisted/twisted/pull/12700 x_refsource_MISC
- https://github.com/twisted/twisted/commit/b53e1c3477c209b5609a1c74cf9e48373b5879ac x_refsource_MISC
- https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1 x_refsource_MISC